Emira V6 Engine Modifications: Let's talk!

[LotusB]

The Achilles heel of the Evora platform, when it comes to power modifications, has been the transmission. Or that's the information I've read and even propagated myself. It's one of the reasons I even debated ordering a v6. I'm used to fast cars and the concern was that the Emira just isn't fast enough, especially with its newly found heft (relative to Evora). I looked past it regardless, reminding myself that I'm not getting the car for racing.

However, deep down I always thought I'd be upgrading it to a "safe-enough" <460hp (intake/exhaust/tune). That should give a little more oomph and upgrade the vocals of an the already well sounding tune. But then I ran across the JUBU Evora 600 HDM. Why is it special? It has 600hp mated to the stock 6-speed manual transmission!

Instantly reached out to JUBU, to get an understanding of what mods I'd need to perform to my transmission to get it to hold ~500hp - which is realistically the limit of where I'd want my car on the street. Well much to my surprise they came back to tell me that the stock transmission, with upgraded gear oil cooling (in their experience) is good for 500hp! I said whaaat??? They said yeahhhh!! I said nawww!! ** Full reaction below **

This information made me so excited, because I've been bemoaning buying the Toyota V6 based powerplant, instead of the much more tunable I4 w/DCT. Don't get me wrong, I still think the I4 will be faster for less money, but all of the sudden I don't feel like I've made a major compromise going for the V6. I'll still have the power, the sound, the manual.... win-win-win.

Now it's just a matter of figuring out how far I want to go with this. Does this information change anything about your modification plans? Share them! I can't be the only crazy one out there, wanting to upgrade a brand new car I haven't even received yet!



Full reaction:

 

[kitkat]

They say transmission, but surely the clutch must be upgraded. Even their site recommends it https://www.jubu-performance.com/en...road__track_mit_schwungrad__starterkranz-2122

 

[VL3X]

They say transmission, but surely the clutch must be upgraded. Even their site recommends it https://www.jubu-performance.com/en...road__track_mit_schwungrad__starterkranz-2122

I'm not so sure. They are using ACT performance clutch/flywheels, which are typically pretty strong.

@LotusB I always heard the stock manual trans is good up to ~450HP. Lots of good info regarding Jubu's claims and the Aisin/Toyota trans here.

 

[d15b7]

I think the question ‘how much Hp is the tranny good for’ is very much based on your use scenario. For instance is this a street car which will never see a racetrack? Or is this a car which will see frequent use on tracks every year? I’d bet that if it’s a street car, then the trans could last years and years with a 500 hp engine. And if it gets tracked regularly, it might be possible to wipe out the tranny in a couple weekends.

Ok that being said - how to make 500+ hp? I come from owning many modded cars; Bringing a 3.5 liter supercharged Japanese V6 up to 500+ isn’t rocket science. You need more boost, and that means more fuel to match it. Then you need more charge cooling (due to making more heat due to more boost). Finally you’ll need more engine coolant cooling (for sure if you are going to track it vs street car). All this is dependant on ‘is the bottom end strong enough to handle the additional stress with stock pistons and rods’. OK:

1. more boost typically = port the supercharger snout. Add bigger throttle body. Change pulley sizes.
2. more fuel = add bigger fuel pump. Add bigger fuel injectors. Add tuning solution (reflash ecu or standalone)
2a. add free flow headers/exhaust
2b. add custom ground camshafts for higher boost higher performance applications.
3. add bigger charge intercooler brick (or water injection/meth injection) to handle additional boost.
4. Upsize radiator. Possible upsize oil cooler (more likely only for track use)
5. some cars come with a bullet proof factory bottom end (for example 2JZ Toyota 6 cyl). I don’t believe that our Emira V6 qualifies as bullet proof (it was born originally to be naturally aspirated for passenger car duty). I’d suggest that at 500+ hp it would want forged rods and pistons to be added.

All very do-able. Find a good tuning shop that is experienced with increasing performance in boosted applications and leave the car there for a bit of time and you’ll get a big power bump. Cost wise this might be a bit painful compared to other mass produced high performance cars with big followings that have readily available ‘Stage Kits’ already developed. For example, I own a ‘20 Camaro ZL1 1LE with the LT4 6.2 liter supercharged V8. It makes 650 hp stock. It is VERY easy to purchase Stage 1 through 4 kits for it (never touching the bottom end) and make upwards of 1000+ hp. There’s multiple shops all over the country that offer these services for this particular car, since the motor is so prolific. Perhaps if enough Emira V6 are sold, some shop in the US might decide to develop some stage kits (as do the couple places in Europe now for the Evora).

 

[LotusB]

I'm not so sure. They are using ACT performance clutch/flywheels, which are typically pretty strong.

@LotusB I always heard the stock manual trans is good up to ~450HP. Lots of good info regarding Jubu's claims and the Aisin/Toyota trans here.

I'm going from memory, but I thought it was something like 460hp for street and 430hp for track.

Even in your link, there's a post that says:

Matt from MWR says "Our evora has been well over 500hp with a turbo and is there now with a supercharger. No issues so far, though to be fair it is not used in endurance racing."

A turbo will generate much more torque than the twin-screw, so that's also a good confirmation.

Also... if I can get results like these: https://www.lotustalk.com/threads/update-on-komotec-475-tune-for-evora-‘21gt.533594/post-6194733 with just an intake/headers/exhaust/tune, I'm not going to rebuild the engine. That's a super healthy increase in torque (scroll down a bit to see the area under the curve!)

 

[hagen111]

Stock engine with little mods is good for 430-440 hp as far as I have been informed.

I always worked on the setup of the car, make it lighter, lower, more firm with really good tires. With 350hp it was very fast on track...especially very fast corners where balance and grip was important.

 

[VL3X]

I'm going from memory, but I thought it was something like 460hp for street and 430hp for track.

Even in your link, there's a post that says:


A turbo will generate much more torque than the twin-screw, so that's also a good confirmation.

Also... if I can get results like these: https://www.lotustalk.com/threads/update-on-komotec-475-tune-for-evora-‘21gt.533594/post-6194733 with just an intake/headers/exhaust/tune, I'm not going to rebuild the engine. That's a super healthy increase in torque (scroll down a bit to see the area under the curve!)

Those are some impressive numbers... Especially from a Mustang dyno! That powerband could be smoothed out a bit though. Still really cool to see! I especially like seeing the twin charged projects.

FWIW, the 2GR-FE features forged steel connecting rods and crankshaft.

 

[hagen111]

I'm going from memory, but I thought it was something like 460hp for street and 430hp for track.

Even in your link, there's a post that says:


A turbo will generate much more torque than the twin-screw, so that's also a good confirmation.

Also... if I can get results like these: https://www.lotustalk.com/threads/update-on-komotec-475-tune-for-evora-‘21gt.533594/post-6194733 with just an intake/headers/exhaust/tune, I'm not going to rebuild the engine. That's a super healthy increase in torque (scroll down a bit to see the area under the curve!)

Once you put your money where your mouth is, you really get to know how things in the real world turn out to be.

Really do your research on how much the later type V6 + supercharger will take without modifying the bottom end.

 

[Evotion]

Interesting stuff.

My car is at Larini where they are building and testing different boxes and setups.
The ultimate setup, just exhaust system wise, realistically speaking, seems to be new manifold, sports cat and new back box.
I don't know if the car then needs a tune bit these changes could jump the car to 430hp. I assume that means no ECU changes. I don't know.

All options will be filmed when I pick up the car in a week or so.
I have asked to get weight savings too.

 

[EspritGuy]

Interesting stuff.

My car is at Larini where they are building and testing different boxes and setups.
The ultimate setup, just exhaust system wise, realistically speaking, seems to be new manifold, sports cat and new back box.
I don't know if the car then needs a tune bit these changes could jump the car to 430hp. I assume that means no ECU changes. I don't know.

All options will be filmed when I pick up the car in a week or so.
I have asked to get weight savings too.

Are you keeping the 12-way seats or replacing with something lighter? Can they at least weigh them (a common question)?

 

[Evotion]

I did speak with Tilletts about seats as their carbon buckets would expect to save 50kg!
However, I really don't think my derriere will approve.

 

[LotusB]

Those are some impressive numbers... Especially from a Mustang dyno! That powerband could be smoothed out a bit though. Still really cool to see! I especially like seeing the twin charged projects.

FWIW, the 2GR-FE features forged steel connecting rods and crankshaft.

Are you sure the rods are forged? I've read the opposite and that they're a weak link.

You can see JUBU's take here:

For implementing performances of more than 460 hp, upgraded steel rods are mandatory to ensure the durability of the engine (OEM connecting rods tend to bend/break at 460+ hp).

Here's Komo-tec's take:

Especially when planning a performance increase (> 460 hp) one should not ignore the basic components of the engine and use our forging components to avoid a capital engine damage!

Now, these statements are probably a bit conservative, given that these upgrades aren't part of Komo-tec's "EV4-475" upgrade.

 

[LotusB]

Once you put your money where your mouth is, you really get to know how things in the real world turn out to be.

Really do your research on how much the later type V6 + supercharger will take without modifying the bottom end.

Not really sure what you're implying here? If you have information, share it. I'm going to put my money where my mouth is, but I'd like to make a decision based on good information. There's usually a lot of folklore and (second-hand) "opinions" in forums. Tough to know what to take seriously, which is why I'm mostly trying to rely on information from companies who tune/race these platforms. There are no guarantees with aftermarket, but they have some interest/skin in the game.

I don't have a problem building the bottom-end, if that's what's needed. I've rebuilt engines, designed turbo systems and tuned ECU's before. Wouldn't be my first rodeo, but a first one in well over a decade.

 

[Concept24]

Interesting stuff.

My car is at Larini where they are building and testing different boxes and setups.
The ultimate setup, just exhaust system wise, realistically speaking, seems to be new manifold, sports cat and new back box.
I don't know if the car then needs a tune bit these changes could jump the car to 430hp. I assume that means no ECU changes. I don't know.

All options will be filmed when I pick up the car in a week or so.
I have asked to get weight savings too.

I'm completely unaware of UK's auto smog restrictions, but here in California, cat-back exhaust systems are no problem unless they exceed noise levels, but any changes to intakes (like true CAI setups) and other engine components require certification to be legal. Garages with smog-testing capabilities do a visual inspection under the hood and under the vehicle. Headers are mostly taboo if they eliminate a pre-cat.

 

[VL3X]

Are you sure the rods are forged? I've read the opposite and that they're a weak link.

I don't know for sure from personal experience or testing, but according to this article, they're forged...

2GR-FE: Engine Basics and Specs​

The 2GR-FE uses an open deck V6 with an aluminum cylinder block and aluminum cylinder heads. This all-aluminum design helps save weight and improve thermal efficiency, ultimately increasing fuel economy.

Inside the 2GR-FE, Toyota uses a DOHC design with 4-valves per cylinder to improve power and efficiency. It also features advanced technologies such as forged steel connecting rods, cast aluminum lower intake manifold, and Toyota’s Dual VVT-i system.

The dual VVT-i system helps increase power and torque while maintaining good efficiency. This VVT system works by adjusting both the intake and exhaust camshaft timing on the fly, allowing the ECU to optimize valve overlay on the fly.

The 2GR’s open deck helps improve the cooling system’s efficiency. However, the open deck design can become a limiting factor when making a ton of horsepower. The open deck design isn’t a problem as long as you aren’t trying to make 600hp or more. Plus, the open deck provides much better cooling, which means better thermal efficiency.

Later versions of this engine used Toyota’s direct injection system, further improving power and efficiency.

• Production Run: 2005 – Current
• Cylinder Block Material: Aluminum
• Cylinder Head Material: Aluminum
• Valvetrain: Dual Over Head Cams – Four-Valve per Cylinder
• Stroke: 83mm
• Bore: 94mm
• Compression Ratio: 10.8:1, 11.8:1, 12.5:1, 13:1
• Horsepower: 268hp to 296hp
• Torque: 248 lb-ft to 260 lb-ft

From a 2GR-FE engine manual:

6. Connecting Rod and Connecting Rod Bearing
" Connecting rods that have been forged for high strength are used for weight reduction.
" Knock pins are used at the mating surfaces of the bearing caps of the connecting rod to minimize the shifting of the bearing caps during assembly.
"The connecting rods and caps are made of high-strength steel for weight reduction.
" Nutless-type plastic region tightening bolts are used on the connecting rods for a lighter design.
"An aluminum bearing is used for the connecting rod bearings.
"The connecting rod bearings are reduced in width to reduce friction.
7. Crankshaft
" A crankshaft made of forged steel, which excels in rigidity and wear resistance, is used.
" The crankshaft has 4 journals and 5 balance weights.

 

[CoryC]

Do we not think it is just a matter of a tune that will give this engine the higher redline and 430 HP? Does anyone know any mechanical differences of the Evora GT430 engine to what they're putting in the Emira?

 

[Evotion]

Is the ECU not 'locked' to external sources so we can't tune it via the ECU?

 

[AndySXV]

Do we not think it is just a matter of a tune that will give this engine the higher redline and 430 HP? Does anyone know any mechanical differences of the Evora GT430 engine to what they're putting in the Emira?

From what I understand no difference other than the mapping and the exhaust. Is it simply that the Emira gets 400bhp, the S variant will be higher and the R variant higher again?

 

[VL3X]

Is it simply that the Emira gets 400bhp, the S variant will be higher and the R variant higher again?

We don't know yet. Nothing has been confirmed about future variants, but I'd say that's a good guess.

 

[Silver Storm]

Is the ECU not 'locked' to external sources so we can't tune it via the ECU?

Good point, that’s what I heard too.